Machine for sawing stone.



No. 759,422. PATBNTBD MAY 10'; 1904.- G. H. DAVIS. MACHINE FOR SAWING STONE.

APPLICATION FILED SEPT. 19, 1902.

' 2 SHEETS-SHEET 1.

H0 MODEL.

No. 759,422. PATBNTED MAY 10, 1904.- G. H.'DAVIS. MACHINE FOR SAWING STONE.

APPLICATION FILED SEPT. 19, 1902.

N0 MODEL. 2 SHEETS-SHEET 2.

Patented Ma; 10, 1904.

PATENT OFFICE.

GEORGE H. DAVIS, OF PROCTOR, VERMONT.

MACHINE FOR SAWING STONE.

SPECIFICATION forming part of Letters Patent No. 759,422, dated May 10, 1904.

Application filed September 19, 1902. Serial No. 124,084. (No model.)

To all whom, it may concern:

Be itknown that I, GEORGE H. DAVIS, a citizen of the United States, residing at Proctor, in the county of Rutland and State of Vermont, have invented a certain new and useful Improvement in Machines for Sawing Stone, of which the following is a full, clear, and exact description.

This invention relates to machines for sawing stone, and more especially to that class of such machines in which a frame has mounted in it one or more blades or saws and to which a reciprocating motion is imparted. As here tofore constructed these frames have been hung from sway-bars by pin-joints connecting the hangers both to the frame and to the swaybars, and in operation there is thus a fixed or constant radius of movement of the blades or saws, the point of contact between the saws and stone being only at the lowest point of the are described by the saws.

In the present invention I provide yielding constantly varying as the frame is reciprocated, thus regulating and equalizing the pressure on the stone and where sand or other abrasive material is used permitting it to get more easily under the saws, and so expedite the cutting, all as I will proceed now more particularly to set forth and finally claim.

In the accompanying drawings,illustrating my invention, in the several figures of which like parts are similarly designated, Figure 1 is a side elevation of sufiicient of an ordinary form of sawing-machine to show my improvement. Fig. 2 is an elevation of the right-hand end of Fig. 1. Fig.3 is asectional elevation showing the details of the improvement. Fig. 4 is a top plan view of the sway-bar with the hanger in cross-section. Fig. 5 is a longitudinal section and partial elevation of a modified form of yielding joint. Fig. 6 is a diagram illustrating the theoretical movement of the frame with fixed pin-joints. Fig. 7 is a diagram illustrating the theoretical movement of the frame with yielding connections with the sway-bars.

The machine-framing, saw-frame, and adjusting and reciprocating mechanisms for the saw-frame are here shown of approved construction and need no description.

The saw-frame l is provided with pin-lugs 2, and the sway-bar 3 is connected with the sliding bearing-blocks 4 in any usual manner. The hangers 5 have eye-bearings 6, which are applied to the pin-lugs 2 on the saw-frame, and these hangers extend through tubes 7 ,fixed in the swaybars,each hanger having a yielding devicesuch as a coiled or other spring, block of rubber, air or fluid cushion or equivalent interposed between its lower end and the tube. In Figs. 1 to 1 this yielding device is shown as a coiled spring 8, mounted upon a springseat plate 9, adjustably applied to the hanger by a nut 10 and expanding against a cap 11, whose movement is limited by contact with the tube. The tube may be closed by a plug l2,adjustabl y secured thereto by a coupling 13. The hanger passes freely through the tube and sway-bar, and above the sway-bar it is provided with another and similar yielding device, shown as a coiled spring 1 1, expanding against a cap-plate 15, held to the hanger by nut 16 and seated in aplate 17, resting upon a plug 18, adjustably connected with the tube by a coupling 19. The plugs 12 and 18 serve also as guides for the moving hangers as they slide up and down relatively to the sway bars. The force of the springs 8 and 1 1 may be regulated with the nuts 10 and 16.

The two hanger-tubes at each end are connected and braced by adjustable straining-bars 20, spreading from the sway-bars, or they may be otherwise held in place.

As one substitute for the coiled spring I have shown in Fig. 5 a fluid or air pressure cylinder 21, suspended from the sway-bar 22 by a rod or tube 28 and having a piston-head 24: applied to the hanger 25, which otherwise may be as usual. In such case there need be no yielding connection immediately with the sway-bar.

As indicated by the diagram Fig. 6, where the radius is constant, the saw-frame moves in an arc of a circle; but as indicated in Fig. 7 the yielding joints provide a variable radius.

Thus the are a indicates the motion of the frame before the saws strike the stone. The horizontal line Z) between the radii 0 (Z indicates the travel of the saws across the stone, during which period the radius is continually varying under the action of the springs, it being shortest on the line 0, and after the line (Z is reached the longest available radius controls, and thereafter there is another are of a circle f described. The return movement from right to left is merely a repetition in reverse of the movements described, and hence there is a rise at each end of the stroke. The springs above the sway-bar are used principally for steadying the gang at the ends of the stroke.

The springs at the lower ends of the hangers are for increasing slightly the pressure of the saws on the stone during the stroke and also for steadying the motion of the gang at the ends of the stroke. The two sets of springs together prevent excessive jumping of the frame at the end of the stroke, but permit Vibration enough to allow the abrasive material to pass under the saws freely. The two springs work together, so that when the gang is high in the frame that is, when the position of the gang is above the level of the crank-shaft, so that the pitman is working on an angle with the horizontalthe lower spring at the pitman end of the frame is very much compressed on the upstroke and the upper spring is compressed on the downstroke. By having the springs on both sides of the sway-bar the jump of the sway-bar is decreased, while the raise of the frame is retained sufliciently to let the sand work under the blades.

The invention is equally applicable to saws with or without teeth or other cutting-surfaces and with or without the use of water and an abrasive.

hat I claim is 1. A stone-sawing machine, having a sawframe, hangers therefor, sway-bars, and yielding connections for the hangers and swaybars arranged upon opposite sides of the sway-bars.

2. A stone-sawing machine, having a reciprocating saw-frame, hangers to which the saw-frame is jointed, sway-bars having fixed depending portions with which the hangers are slidably connected, and yielding devices interposed between the hangers and their sway-bar connections.

3. A stone-sawing machine, having a reciprocating saw frame, hangers to which the saw-frame is jointed, sway-bars having fixed depending portions with which the hangers are slidably connected, and springs interposed between the hangers and their sway-bar connections.

4:. A stone-sawing machine, having a reciprocating saw-frame, sway-bars provided with fixed depending tubes, hangers attached to said saw-frame and extending up through said tubes, and yielding devices interposed between said tubes and hangers, whereby the radius of movement of the hangers is varied.

5. A stone-sawing machine, having a reciprocating saw-frame, sway-bars provided with fixed depending tubes, hangers attached to said saw-frame and extending up through said tubes,and coiled springs interposed between said tubes and hangers, whereby the radius of movement of the hangers is varied.

In testimony whereof I have hereunto set my hand this 11th day of September, A. D. 1902.

GEORGE H. DAVIS.

Witnesses:

HELEN M. GILLEsrIn, MARY J. GILL. 

